W221 intermittent limp mode ABS/ESP inoperative

Megz92

New Member
Joined
Apr 16, 2021
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10
Location
Scotland
Car
2006 W221 S-Class S320 CDi
Hoping someone can help me please! Bit of a long post so apologies in advance.

I have a 2006 S-Class S320 CDI (W221).
Bought it a few weeks ago and up until now the car has been sitting since its last MOT in July.

When we got the car there is a message on the dash saying ABS/ESP inoperative. Run Flat Indicator inoperative. We don't have the owners manual for the car so can't consult it as it says.

Partner plugged his diagnostic into the car and it came up with a faulty wheel speed sensor passenger rear. We bought a new sensor and fitted it, reset the fault but fault still on the dash. It'll turn off until the car moves a few feet and it'll come on again.

The car went into limp mode one day coming out of the fuel station. Managed to get off the road and phone partner but of course by the time he arrived to save the day it was fine again and no faults found on the car. Not had it do this again for a couple of weeks until today again.

While driving the dash came up with the manual/electronic handbrake and the car wouldn't change gear. Restarted the car mid driving as I was in peak traffic and it went away but then went into limlp mode. Again, checked diagnostic, no faults other than the esp/abs/electronic break system. When I started the car again the steering went heavy and went back into limp mode. Stopped the car again and turned it off and it sounded like it was overheating but temperature was sitting just over 80degrees. At one point while driving on the dual carriageway the glow plug light came on but soon went off again.

Anyone have any ideas as to what's going on?
 

W1ghty

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Jun 27, 2020
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2,139
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Sunny Essex
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E320cdi and CLK200
Can’t help with the technical side , but MB’s really hate low voltage . Has the battery been fully charged or is it way past its best .
Low voltage can throw up some weird and wonderful faults
There should be a date for the battery on one of the terminals
 
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Megz92

Megz92

New Member
Joined
Apr 16, 2021
Messages
10
Location
Scotland
Car
2006 W221 S-Class S320 CDi
Can’t help with the technical side , but MB’s really hate low voltage . Has the battery been fully charged or is it way past its best .
Low voltage can throw up some weird and wonderful faults
There should be a date for the battery on one of the terminals
We had to do this already, yeah. The central locking wouldn't work, boot wouldn't open, windows wouldn't go down sometimes so took the new battery out the OHs MB as its SORN.
Took the old battery out behind the back seats and it only tested at 3 Volts and turns out it was the original 😂 everything has been fine since then until today. The front battery is relatively new too so don't think it'll be that but we'll test that one too just to be safe.
 

zipdip

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Mar 5, 2015
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3,982
Location
Essex
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s320
Welcome aboard your car has two batteries,the battery that starts the car is under the hood where you would expect a battery to be,the bigger battery that runs everything else,is behind the rear seat ,this can only be accessed by removing spare wheel cover and I have always found if you remove one side of the boot covering,you can then remove the panel at the back of the boot the battery is easy to remove,best to buy a cheap battery tester to check it,maybe charge it up and try the old battery to see if it sorts the problems, check the age of the battery if it is more than 7 years old best buy a new one.
 
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Megz92

Megz92

New Member
Joined
Apr 16, 2021
Messages
10
Location
Scotland
Car
2006 W221 S-Class S320 CDi
Welcome aboard your car has two batteries,the battery that starts the car is under the hood where you would expect a battery to be,the bigger battery that runs everything else,is behind the rear seat ,this can only be accessed by removing spare wheel cover and I have always found if you remove one side of the boot covering,you can then remove the panel at the back of the boot the battery is easy to remove,best to buy a cheap battery tester to check it,maybe charge it up and try the old battery to see if it sorts the problems, check the age of the battery if it is more than 7 years old best buy a new one.
We had a new battery put in behind the seats as it was only reading 3v. New battery sitting at 13v and the battery in the boot at over 14v so confident it's not the battery 😣
 

mbmbc123

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Joined
May 2, 2013
Messages
12
Car
w203 c220cdi
Where did you get the wheel speed sensor from. It's not unheard of for new parts to be faulty. I've seen this issue twice. The first time on a 2008 s320. The garage replaced the reluctor ring, the thing the speed sensor is sensing as the wheel turns. The second time was on a 2012 s350. I replaced the speed sensor with a £100 MB dealer part. Problem solved. You can go cheaper, and i probably will next time, but will a cheaper part work.

I suspect the problem you have with an older car is that the ring has rusted and partially disintegrated. Cant be sure, but have seen this on other old cars.
 
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Megz92

Megz92

New Member
Joined
Apr 16, 2021
Messages
10
Location
Scotland
Car
2006 W221 S-Class S320 CDi
Where did you get the wheel speed sensor from. It's not unheard of for new parts to be faulty. I've seen this issue twice. The first time on a 2008 s320. The garage replaced the reluctor ring, the thing the speed sensor is sensing as the wheel turns. The second time was on a 2012 s350. I replaced the speed sensor with a £100 MB dealer part. Problem solved. You can go cheaper, and i probably will next time, but will a cheaper part work.

I suspect the problem you have with an older car is that the ring has rusted and partially disintegrated. Cant be sure, but have seen this on other old cars.
So we are literally just back from having another look at the sensor. Got it from autodoc. Have just now discovered that the abs ring is shot. It's separated and just spinning in the shaft 🙄 so we've ordered 2 new ones because the diagnostic is showing both rear abs sensors at fault so just changing both sides sensors and rings and hoping that sorts it. Will be doing bearings at the same time as they'll need done for next MOT so surely after all that, it'll sort the issue🤞🍀
 

Nicebutdim

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Jul 5, 2017
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614
Car
E320 cdi avantgarde 2007. Honda Goldwing GL1800. 1975 Norton 850 Commando. 1975 Suzuki GT750.
Within the last month my 2007 w211 e320 cdi developed exactly the same symptoms except the fault code pointed to the front wheel.

At start up the car would show no fault. Take speed above 10mph ......result, limp mode, no esp, abs, power steering and tyre pressure monitor. Park car overnight and same pattern next morning.

Fault scanner suggested check gap between sensor and rotating magnetic reluctor.

I replaced the front wheel bearing which included a new reluctor. The reluctor had to be accurately pressed into the bearing housing avoiding any damage and ensuring a close gap with the sensor.

This solved the problem and everything now back to normal. Good luck. Sounds like you’re on the right track.
 

morrisman

Member
Joined
Apr 11, 2021
Messages
36
Location
leeds
Car
e320cdi estate
Within the last month my 2007 w211 e320 cdi developed exactly the same symptoms except the fault code pointed to the front wheel.

At start up the car would show no fault. Take speed above 10mph ......result, limp mode, no esp, abs, power steering and tyre pressure monitor. Park car overnight and same pattern next morning.

Fault scanner suggested check gap between sensor and rotating magnetic reluctor.

I replaced the front wheel bearing which included a new reluctor. The reluctor had to be accurately pressed into the bearing housing avoiding any damage and ensuring a close gap with the sensor.

This solved the problem and everything now back to normal. Good luck. Sounds like you’re on the right track.
good info
 

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